PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Gold nanoparticles give an edge in recycling CO2

2013-10-25
(Press-News.org) Contact information: Kevin Stacey
kevin_stacey@brown.edu
401-863-3766
Brown University
Gold nanoparticles give an edge in recycling CO2

PROVIDENCE, R.I. [Brown University] — By tuning gold nanoparticles to just the right size, researchers from Brown University have developed a catalyst that selectively converts carbon dioxide (CO2) to carbon monoxide (CO), an active carbon molecule that can be used to make alternative fuels and commodity chemicals.

"Our study shows potential of carefully designed gold nanoparticles to recycle CO2 into useful forms of carbon," said Shouheng Sun, professor of chemistry and one of the study's senior authors. "The work we've done here is preliminary, but we think there's great potential for this technology to be scaled up for commercial applications."

The findings are published in the Journal of the American Chemical Society.

The idea of recycling CO2 — a greenhouse gas the planet current has in excess — is enticing, but there are obstacles. CO2 is an extremely stable molecule that must be reduced to an active form like CO to make it useful. CO is used to make synthetic natural gas, methanol, and other alternative fuels.

Converting CO2 to CO isn't easy. Prior research has shown that catalysts made of gold foil are active for this conversion, but they don't do the job efficiently. The gold tends to react both with the CO2 and with the water in which the CO2 is dissolved, creating hydrogen byproduct rather than the desired CO.

The Brown experimental group, led by Sun and Wenlei Zhu, a graduate student in Sun's group, wanted to see if shrinking the gold down to nanoparticles might make it more selective for CO2. They found that the nanoparticles were indeed more selective, but that the exact size of those particles was important. Eight nanometer particles had the best selectivity, achieving a 90-percent rate of conversion from CO2 to CO. Other sizes the team tested — four, six, and 10 nanometers — didn't perform nearly as well.

"At first, that result was confusing," said Andrew Peterson, professor of engineering and also a senior author on the paper. "As we made the particles smaller we got more activity, but when we went smaller than eight nanometers, we got less activity."

To understand what was happening, Peterson and postdoctoral researcher Ronald Michalsky used a modeling method called density functional theory. They were able to show that the shapes of the particles at different sizes influenced their catalytic properties.

"When you take a sphere and you reduce it to smaller and smaller sizes, you tend to get many more irregular features — flat surfaces, edges and corners," Peterson said. "What we were able to figure out is that the most active sites for converting CO2 to CO are the edge sites, while the corner sites predominantly give the by-product, which is hydrogen. So as you shrink these particles down, you'll hit a point where you start to optimize the activity because you have a high number of these edge sites but still a low number of these corner sites. But if you go too small, the edges start to shrink and you're left with just corners."

Now that they understand exactly what part of the catalyst is active, the researchers are working to further optimize the particles. "There's still a lot of room for improvement," Peterson said. "We're working on new particles that maximize these active sites."

The researchers believe these findings could be an important new avenue for recycling CO2 on a commercial scale.

"Because we're using nanoparticles, we're using a lot less gold than in a bulk metal catalyst," Sun said. "That lowers the cost for making such a catalyst and gives the potential to scale up."



INFORMATION:

The work was funded by a National Science Foundation grant to the Brown-Yale Center for Chemical Innovation (CCI), which looks for ways to use CO2 as a sustainable feedstock for large-scale commodity chemicals. Other authors on the paper were Önder Metin, Haifeng Lv, Shaojun Guo, Christopher Wright, and Xiaolian Sun.

Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.



ELSE PRESS RELEASES FROM THIS DATE:

Aboriginal hunting practice increases animal populations

2013-10-25
Aboriginal hunting practice increases animal populations Burning approach mixing practical philosophy and knowledge leads to near doubling of lizards and improves habitat

Children with brain injuries nearly twice as likely to suffer from depression

2013-10-25
Children with brain injuries nearly twice as likely to suffer from depression Findings may help to identify, treat children at risk of depression ORLANDO, Fla. —Adults with head injuries are known to be at high risk for depression, and yet little research ...

Portable vision screening devices accurately identify vision problems in young children

2013-10-25
Portable vision screening devices accurately identify vision problems in young children New guidelines and technical advances likely to increase amblyopia screening in pediatric practice ORLANDO, Fla. —Portable screening devices allow pediatricians to successfully ...

Sleep apnea is associated with subclinical myocardial injury

2013-10-25
Sleep apnea is associated with subclinical myocardial injury Obstructive sleep apnea is known to be associated with an increased incidence of cardiovascular disease. Now a new study indicates that OSA is associated with subclinical myocardial injury, as indicated by ...

USC researcher reveals how to better master stem cells' fate

2013-10-24
USC researcher reveals how to better master stem cells' fate USC scientist Qi-Long Ying and a team of researchers have long been searching for biotech's version of the fountain of youth — ways to encourage embryonic stem cells (ESCs) and epiblast stem ...

Using sound waves for remote bomb detection

2013-10-24
Using sound waves for remote bomb detection A remote acoustic detection system designed to identify homemade bombs can determine the difference between those that contain low-yield and high-yield explosives. That capability – never before reported ...

Study: Metformin for breast cancer less effective at higher glucose concentrations

2013-10-24
Study: Metformin for breast cancer less effective at higher glucose concentrations A University of Colorado Cancer Center study published online this month in the journal Cell Cycle shows that breast cancer cell growth, motility and aggression is promoted by excess ...

NEJM study exposes overuse of radiation therapy when urologists profit from self-referral

2013-10-24
NEJM study exposes overuse of radiation therapy when urologists profit from self-referral IMRT use is 2 1/2 times greater when self-referral's financial incentives are involved Fairfax, Va., October 23, 2013—A comprehensive review of Medicare ...

UCLA sleep apnea study uncovers more hidden dangers for women

2013-10-24
UCLA sleep apnea study uncovers more hidden dangers for women There's more bad news for women with sleep apnea. A new study from the UCLA School of Nursing shows that the body's autonomic responses — the controls that impact such functions as blood ...

USC study: Google search serves users from 600 percent more locations than a year ago

2013-10-24
USC study: Google search serves users from 600 percent more locations than a year ago In a shift in strategy, Google reuses existing content delivery infrastructure to speed up searches Over the past 10 months, Google search has dramatically increased the ...

LAST 30 PRESS RELEASES:

Transnational electoral participation of undocumented Mexican immigrants in the US

A new method to build more energy-efficient memory devices for a sustainable data future

Freely levitating rotor spins out ultraprecise sensors for classical and quantum physics

‘Chinese lantern’ structure shifts into more than a dozen shapes for various applications

Towards light-controlled electronic components

Tiny architects, titanic climate impact: scientists call for October 10 to become International Coccolithophore Day

Stress sensitivity makes suicidal thoughts more extreme and persistent among the university population

Lessons from Ascension’s shark troubles could help boost conservation

Fire provides long-lasting benefits to bird populations in Sierra Nevada National Parks

Menstrual cycle affects women’s reaction time but not as much as being active

Housing associations more effective than government in supporting unemployed in deprived areas

Biochar helps composting go greener by cutting greenhouse gas emissions

Ulrich named president-elect of the AACI

Multitasking makes you more likely to fall for phishing emails

Researchers solve model that can improve sustainable design, groundwater management, nuclear waste storage, and more

Parched soils can spark hot drought a nation away

Uncovering new physics in metals manufacturing

Sped-up evolution may help bacteria take hold in gut microbiome, UCLA-led research team finds

The dose-dependent effects of dissolved biochar on C. elegans: Insights into the physiological and transcriptomic responses

New research reveals genetic link to most common pediatric bone cancer

Research conducted during 2024 eclipse reveals importance of light on bird behavior

Why does female fertility decline so fast? The key is the ovary

Total solar eclipse triggers dawn behavior in birds

Europe’s largest bats hunt and eat migrating birds on the wing, high in the sky

China’s emerging AI regulation could foster an open and safe future for AI

The secret to naked mole-rat’s longevity: Enhanced DNA repair

Acidic tumor environment promotes survival and growth of cancer cells

New biosensor tracks plants’ immune hormone in real time

New study finds gaps in REDD+ forest carbon offsets with most overstating climate impacts

Mystery solved: How Europe’s largest bat catches and eats passerines mid-air

[Press-News.org] Gold nanoparticles give an edge in recycling CO2